Family Alpheidae

Snapping shrimp

Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Crustacea
Class:	Malacostraca
Order:	Decapoda
Infraorder:	Caridea
Superfamily:	Alpheoidea
Family:	Alpheidae Rafinesque, 1815

These little creatures make the incessant pops that you hear at low tide. They are found on sand, mudflats and coral rubble. They range from tiny ones to rather large ones that can pack a really loud pop. Some even hide under carpet anemones and inside sponges or other animals. During the day, the snapping shrimp hides in a burrow, sometimes renovating it quietly. It forages more actively at night.

The snapping sound is not made by the fingers actually hitting each other. Rather, a high-speed jet of water shoots out due to the extremely rapid compression of the fingers. This jet vapourises the water and creates a bubble. When the bubble collapses, the sound results. Not only that, a flash of light is also emitted! These findings are possibly useful for naval applications as the sound of snapping shrimps seriously interfere with sonar detection in shallow seas. In fact, snapping shrimps have been studied since World War II as their sounds interfered with the detection of hostile submarines!


Credits: http://www.wildsingapore.com/wildfacts/crustacea/othercrust/shrimp/alpheidae.htm